Liquid supply method, capillary force generating member container used for method thereof, and liquid supply container

ABSTRACT

A liquid supply method using a liquid supply system has a capillary force generating member container, an atmospheric air communication portion a liquid supply portion, a communication portion and a liquid supply container. A capillary force generating member container has a capillary force generating member, a communication portion, an atmospheric air communication portion and a liquid supply portion, and a liquid supply container that can be attached to and removed from a capillary force generating member container having a capillary force generating member an atmospheric air communication portion and a liquid supply portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ink tank preferably used for anink-jet recorder or the like, particularly to a liquid supply method inwhich a part of a container can be changed.

2. Related Background Art

A conventional ink-jet recorder uses an ink tank for storing ink by anegative pressure generated by a capillary force as an ink tank forstoring a liquid (ink) to be attached to a recording medium to performrecording and supplying the ink to an ink-jet recording head fordischarging the ink to the recording medium.

The most general configuration of the ink tank uses the capillary forceof a porous body and includes a porous body such as sponge set orpreferably compressively set in the whole ink tank to store ink and anatmospheric air communication portion capable of introducing air into anink storage portion for smoothly supplying ink under printing.

However, the ink tank using the porous member as a capillary forcegenerating member for storing ink has a low ink-storage efficiency forunit volume. Therefore, the present applicant proposes an ink tankcomprising a capillary force generating member container for storing acapillary-force generation member and a liquid supply container forstoring the ink to be supplied to the capillary force generating membercontainer though a communication portion in Japanese Patent ApplicationLaid-Open No. 7-125232. That is, in case of the above configuration,because the liquid supply container stores only ink, the ink storageefficiency is improved by storing ink in the container.

The liquid supply container is substantially closed except thecommunication portion and the capillary force generating membercontainer is exposed to the atmospheric air through the atmospheric aircommunication portion. When ink is supplied from the liquid supplyportion, air is introduced into the capillary-force generation memberfrom the atmospheric air communication portion through a buffer chamberand the ink is supplied to the capillary-force generation portion fromthe liquid supply container while the air is introduced into the liquidsupply container from the capillary-force generation member. Ink issupplied to the capillary force generating member container from theliquid supply container in accordance with gas-liquid change operation.

Moreover, the present applicant proposes an invention making it possibleto change liquid containers of an ink tank having the above structure inJapanese Patent Application Laid-Open No. 6-226990. According to theinvention, it is possible to repeatedly use a capillary force generatingmember container by consuming the ink in the liquid supply container andthereafter, changing the empty liquid supply container to a new liquidsupply container filled with ink.

On the other hand, the present applicant proposes an ink tank using afiber body made of a thermoplastic olefin-based resin (e.g.polypropylene or polyethylene) as a capillary-force generation member ofthe ink tank in Japanese Patent Application Laid-Open No. 8-20115. Theink tank is superior in ink storage stability and moreover superior inrecycling characteristic since both the body of the ink tank and thefiber body are made of the same kind of material.

SUMMARY OF THE INVENTION

The present inventor et al. studied a liquid supply method using theabove gas-liquid change system and resultantly obtained new informationfor flow and change of liquid and gas introduction about connectionposition and setting/removal between a liquid supply container and anegative pressure generating member container.

That is, the present inventor et al. completed a new liquid supplymethod by setting a plurality of liquid storage members (sponges orfiber bodies or the like serving as negative pressure generatingmembers) in a negative pressure generating member container, noticingthe positional relation between their contact faces of the storagemembers and joints of a liquid supply container with the members, andtechnically analyzing a configuration or system for further improving aliquid supply performance.

A liquid supply method according to the present invention is a liquidsupply method according to a liquid supply system comprising a liquidsupply container having a liquid storage portion for storing liquid in aclosed, a capillary-force generation member which can be set to orremoved from the liquid supply container and hold the liquid, anatmospheric air communication portion for communicating with atmosphericair, and a capillary force generating member container provided with aliquid supply portion for supplying liquid to the outside, which isapplied to a system using at least two liquid storage members made offiber and contacted each other as the capillary force generating member.

As a result of studying the above liquid supply system, the presentinventor et al. obtained the following three aspects.

(First aspect)

It is a first aspect according to the present invention that at the timeof taking a liquid supply container out of a capillary force generatingmember container, movement of the ink left in a communication portion toa capillary force generating member is changed due to the relationbetween the position of a contact face of the liquid storage member andthe position of the communication portion.

In this first aspect, it is characterized that the contact face ispresent below the upper end of the communication portion.

(Second aspect)

It is a second aspect according to the present invention that movementof gas during gas-liquid change operation is changed due to the relationbetween the position of a contact face and that of a communicationportion.

In this second aspect, it is characterized that the contact face ispresent below the upper end of the communication portion and above thelower end of the communication portion.

Even if a gas-liquid interface lowers as ink is consumed and the levelof ink in a liquid supply container lowers, lowering of the gas-liquidinterface is controlled by the contact face in the communicationportion. Therefore, air is introduced into a liquid supply containerfrom the upper side of the communication portion before it is introducedinto a lower absorption body (liquid storage member) and thereby, theink discharged out of the liquid supply container is directly dischargedto the lower absorption body (liquid storage member).

Therefore, it is possible to sequence operations and make the operationssecurely function so as to first, consume the ink in the upperabsorption body and the ink in the liquid supply container throughgas-liquid change operation and thereafter consume the ink in the lowerabsorption body (liquid storage member).

(Third aspect)

It is a third aspect according to the present invention that inkmovement in a capillary force generating member container when connectedwith a liquid supply container is changed due to the relation betweenthe position of a contact face and that of a communication portion.

In this third aspect, it is characterized that the contact face ispresent below the lower end of the communication portion.

When the liquid supply container is connected to the capillary forcegenerating member container in which ink is consumed and the ink isinjected into the liquid supply container, the injected ink controls agas-liquid interface once by a pressure-welding face because the contactface is formed at the lower side of the communication portion.Therefore, it is possible to immediately stabilize the gas-liquidinterface of the injected ink.

The present invention is summarized by an invention of “locating acontact face below the upper end of a communication portion” as thesynthesis of these first to third aspects.

Under the normal operating state in which a liquid supply container isconnected with a capillary force generating member container, agas-liquid interface L is formed nearby the upper end of a communicationportion. Therefore, in case of a liquid supply method of the presentinvention, a gas-liquid interface is formed in the upper capillary forcegenerating member in two liquid holding members contacted each otherunder the normal operating state. Therefore, the liquid (ink) left inthe communication portion at the time of taking the liquid supplycontainer out of the capillary force generating member container isabsorbed in the capillary force generating member container as thegas-liquid interface rises in the upper capillary force generatingmember. Thus, the ink left in the communication portion can be smoothlyabsorbed because it can be avoided that a gas-liquid interface reachesthe contact face between two liquid holding members due to absorption ofink and an ink absorption rate is decreased because the gas-liquidinterface is not easily moved above the contact face like the case ofthe conventional example. Moreover, when setting the position of thecontact face below the upper end of the communication portion and abovethe lower end of the communication portion, it is possible to preventthe gas-liquid interface from moving to the lower liquid holding memberand consume the ink in the upper liquid holding member and thereafter,consume the ink in the lower liquid holding member by introducing an airinto the liquid supply container. Furthermore, when connecting theliquid supply container to the capillary force generating membercontainer in which ink is consumed and injecting ink into the container,because the contact face is formed at the lower side of thecommunication portion, the injected ink controls the gas-liquidinterface once by the pressure welding face and thereby, it is possibleto immediately stabilize the gas-liquid interface of the injected ink.

Moreover, by forming a configuration so that the contact face is presentbelow the lower end of the communication portion, a gas-liquid interfacecan be more securely formed above the contact face between two capillaryforce generating members and the above action can be securely obtained.That is, even if ink is consumed and the gas-liquid interface lowers asthe level of the ink in the liquid supply container lowers, thegas-liquid interface may not easily lower below the lower end of thecommunication portion as long as ink remains. Therefore, the gas-liquidinterface may not easily move below the contact face between two liquidholding members.

A liquid supply method of the present invention makes it possible thatthe ink in an upper-side liquid holding member smoothly moves into alower-side liquid holding member as the ink in a lower-side liquidholding member is consumed when the ink is consumed from a state inwhich the ink is held by two liquid holding members by using aconfiguration in which the dynamic resistance of the liquid in theliquid holding member upper than a contact face is smaller than thedynamic resistance of the liquid in the liquid holding member lower thanthe contact face and thereby, it is possible to control that agas-liquid interface deforms and moves below the contact face betweentwo liquid holding member.

Moreover, the above configuration makes it possible to smoothly absorbink because the ink left in a communication portion when removing aliquid supply container from a capillary force generating membercontainer contacts with an upper liquid holding member having a smalldynamic resistance. Furthermore, by using a configuration in which thecontact face between two liquid holding members is present below thelower end of a communication portion as described above, only an upperliquid holding member contacts with the opening face of thecommunication portion. Therefore, the ink left in the communicationportion can be smoothly absorbed because the ink securely contacts withan upper liquid holding member.

Furthermore, by using a configuration in which the capillary force of aliquid holding member upper than a contact face is smaller than that ofa liquid holding member lower than the contact face, ink can beeffectively supplied to the lower liquid holding member from the upperliquid holding member before the ink held by the liquid member upperthan the contact face is completely consumed. Therefore, it is possibleto realize a configuration in which ink shortage does not easily occur.

By using a configuration in which the fiber density of a liquid holdingmember upper than a contact face is lower than that of a liquid holdingmember lower than the contact face, it is possible to realize aconfiguration in which a liquid holding member upper than a contact facehas a smaller dynamic resistance of the ink in a member and a smallercapillary force.

Moreover, by using a fiber member in which main fiber directions areoriented to the same direction as a capillary force generating member,the ink moving in the member has a large dynamic resistance in adirection perpendicular to the fibers because the fibers interruptmovement of the ink but it has a small dynamic resistance in thedirection parallel with the fibers. Therefore, by setting main fiberdirections of a liquid holding member to an almost-horizontal directionin the operating attitude of the fibers, it is possible to stabilize agas-liquid interface on a horizontal plane and prevent ink shortage fromoccurring because the gas-liquid interface deforms and a part of theinterface reaches a liquid supply portion. By setting a layer in whichdirections of fibers are oriented to the same direction at least nearbythe upper end of a communication portion on which a gas-liquid interfaceis formed under the normal operating state, it is possible to achievethe above effect.

Moreover, by bringing a liquid holding member having a capillary forcelarger than that of other liquid holding portion into contact with aliquid supply portion, it is possible to effectively introduce ink tothe liquid supply portion and efficiently completely consume the ink.

Furthermore, by setting main fiber directions of the liquid holdingmember of the liquid supply portion to the direction parallel with anink supply direction, it is possible to efficiently supply ink becausethe ink in the ink supply direction has a small dynamic resistance.

Furthermore, when a communication portion and a liquid supply portionare located at the same height, some of the ink moving from acommunication portion up to a liquid supply portion in a capillary forcegenerating member is introduced into the liquid supply portion aftertemporarily moving upward when a gas-liquid interface is raised due toan environmental change and may pass through a path longer than the pathof the ink linearly moving from the communication portion up to theliquid supply portion. Thus, when there is a difference between lengthsof ink paths, fluctuation occurs in components of inks supplied from theliquid supply portion after passing through paths different from eachother in length. Therefore, by setting the communication portion abovethe liquid supply portion, the ink moving from the communication portionto the liquid supply portion passes through a comparatively longdownward path and the length of an ink path is almost determined by thelength of the downward path. Therefore, it is possible to control thefluctuation in lengths of ink paths and reduce the fluctuation incomponents of inks supplied from a liquid supply portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an ink-jet head cartridge of afirst embodiment according to the present invention;

FIG. 2 is a sectional view of the cartridge in FIG. 1;

FIGS. 3A and 3B are perspective views for explaining an ink tank unitshown in FIG. 2;

FIGS. 4A, 4B, 4C and 4D are sectional views for explaining operationsfor setting the ink tank unit to a holder provided with a negativepressure control chamber unit in FIG. 2;

FIGS. 5A, 5B, 5C, 5D and 5E are sectional views for explainingopening/closing operation of a valve operating mechanism that can beapplied to the present invention;

FIG. 6 is a sectional view for explaining an ink supply operation by theink-jet head cartridge shown in FIG. 2;

FIG. 7 is an illustration for explaining an absorption body in anegative pressure control chamber container shown in FIG. 2;

FIGS. 8A and 8B are illustrations for explaining an absorption body inthe negative pressure control chamber container shown in FIG. 2;

FIG. 9 is a schematic illustration of the ink-jet head cartridge usingthe ink tank unit that can be applied to the present invention;

FIG. 10 is an illustration showing a schematic configuration of arecorder to which the ink-jet head cartridge of the present inventioncan be applied;

FIG. 11 is an illustration for explaining dimensions of components of ajoint of the ink tank unit that can be applied to the present invention;

FIG. 12 is an illustration showing a state in which the ink tank unit ofthe ink-jet cartridge shown in FIG. 2 is removed;

FIG. 13 is a sectional view showing the ink-jet head cartridge of asecond embodiment according to the present invention; and

FIG. 14 is a sectional view showing the ink-jet head cartridge of athird embodiment according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described below byreferring to the accompanying drawings.

The “hardness” of a capillary force generating member of the presentinvention represents the “hardness” when the capillary force generatingmember is stored in a capillary force generating member container, whichis specified by a gradient (kgf/mm) of a repulsion to a deformation ofthe capillary force generating member. When there are two capillaryforce generating members having “hardnesses” different from each other,a capillary force generating member having a larger gradient ofrepulsion to a deformation is defined as a “hard capillary forcegenerating member”.

First Embodiment

<Whole configuration>

FIG. 1 shows a perspective view of an ink-jet head cartridge of anembodiment of the present invention and FIG. 2 shows a sectional view ofthe cartridge in FIG. 1.

In FIG. 2, it is assumed that the contact face 113 c is provided betweenan upper absorption body 130 and a lower absorption body 140 and the inklevel (hereafter referred to as gas-liquid interface) of the absorptionbodies are L and the upper end of a joint pipe (communication portion)between a negative pressure control unit 100 and an ink-tank unit 200which store the absorption bodies is UP and the lower end of the jointpipe is LP.

As previously described, in the case of a viewpoint how movement of gasin the gas-liquid change operation of the present invention changes to acontact face, a point how the contact face contributes to movement ofgas results from the following study.

When the contact face 113 c is formed above the lower end LP of andbelow the upper end UP of the joint pipe, the gas-liquid interface Lmoves toward an ink supply port in the upper absorption body 130 inaccordance with consumption of ink. In this case, when supplying the inkat a high flow rate, fluctuation in densities of capillary forcegenerating members in the lower absorption body 140 occurs and thereby,lowering of the gas-liquid interface L may fluctuate. However, becauselowering of the gas-liquid interface L is temporarily controlled by thecontact face 113 c at the upper portion of the LP, the upper portion ofthe joint port communicates with air before the gas-liquid interface Lmoves to the lower absorption body and gas-liquid change is started. Inthis case, air is taken in from the upper portion of the joint port tothe ink tank and discharged ink is flows to the lower absorption body140 from the lower portion of the joint port.

Thus, the knowledge is obtained that it is possible to control the flowof ink so that the ink in the upper absorption body is consumed evenwhen supplying the ink at a high flow rate, and gas-liquid change isstarted in the ink tank, and the ink in the lower absorption body isconsumed after consuming the ink in the ink tank.

The following embodiment will be described by including these contents.

Then, the background of noticing ink diffusion into an absorption bodywhen connecting an ink tank of the present invention described abovewill be described below.

When the contact face 113 c is formed above the UP, the ink tank isconnected, and ink is introduced into the negative pressure controlchamber container from the joint port, the gas-liquid interface L of theink entering the lower ink absorption body 140 may fluctuate.

When the contact face 113 c is formed above the LP and below the UP, theink tank is connected, and ink is introduced into the negative pressurecontrol chamber container from the joint port, the gas-liquid interfaceL of the ink entering the lower ink absorption body 140 may fluctuate.

Moreover, because the contact face 113 c is set in the joint port, inkis positively absorbed by the contact face. Therefore, ink may besupplied to the upper absorption body while leaving air in the lowerabsorption body.

When the contact face 113 c is formed below the LP, the ink tank isconnected, and ink is introduced into the negative pressure controlchamber container from the joint port, the ink entering the lowerabsorption body 140 is positively absorbed by the contact face 113 cpresent at the lower portion of the joint port. Therefore, thegas-liquid interface L in the absorption body is controlled below thejoint port. Therefore, the knowledge is obtained that the ink introducedthereafter is introduced onto the gas-controlled liquid interface andthereby, it is possible to control the fluctuation of the gas-liquidinterface L.

The above mentioned can be also understood by the following embodiment.

This embodiment describes elements constituting an ink-jet headcartridge to which the present invention is applied and their relations.Because this embodiment has configurations to which may new arts madewhen the present invention was effectuated are applied, the whole ofthis embodiment will be described while describing these configurations.

As shown in FIGS. 1 and 2, the ink-jet head cartridge of this embodimentis constituted of an ink-jet head unit 160, a holder 150, a negativepressure control chamber unit 100, an ink tank unit (liquid supplycontainer) 200, or the like. The negative pressure control chamber unit100 is fixed in the holder 150 and the ink-jet head unit 160 is fixedbelow the negative pressure control chamber unit 100 through a holder.In this case, the holder 150 and negative pressure control chamber unit100 and the holder 150 and ink-jet head unit 160 are respectively fixedeach other through screws or engagement so that they can be easilydisassembled. This is effective for recycling, decrease in cost for achange of configurations such as changes in the version or the like, orthe like. Moreover, easy disassembly is also preferable from theviewpoint that only a component to be changed can be easily changedbecause service lives of components are different from each other.However, it is a matter of course that it is permitted to completely fixa component through welding or thermal caulking, depending on thecondition. The negative pressure control chamber unit 100 is constitutedof a negative pressure control chamber container (capillary forcegenerating member container) 110 on whose upper face an opening isformed, a negative pressure control chamber lid 120 set to the upperface of the negative pressure control chamber container 110, and twoabsorption bodies (capillary force generating members) 130 and 140 setin the negative pressure control chamber container 110 to impregnate andhold ink. The absorption bodies 130 and 140 are vertically superposed attwo stages under the operating state of the ink-jet head cartridge andset in the negative pressure control chamber vessel 110 by being closelycontacted each other. Because a capillary force generated by thelower-stage absorption body 140 is higher than a capillary forcegenerated by the upper-stage absorption body 140, the lower-stageabsorption body 140 has a higher ink-holding force. The ink in thenegative pressure control chamber unit 100 is supplied to the ink-jethead unit 160 through an ink supply pipe 165.

A filter 161 is set to a supply port (liquid supply portion) 131 of thefront end of the ink supply pipe 165 at the absorption body-140 side,which pushes the absorption body 140. The ink tank unit 200 isconstituted so as to be removable from the holder 150. A joint pipe(communication portion) 180 serving as a joined portion provided for theface of the negative pressure control chamber container 110 at the inktank unit-200 side is inserted into and connected with a joint port 230of the ink tank unit 200. The negative pressure control chamber unit 100and ink tank unit 200 are constituted so that the ink in the ink tankunit 200 is supplied into the negative pressure control chamber unit 100through the joint between the joint pipe 180 and the joint port 230. AnID member 170 protruded from the face of the negative pressure controlchamber container 110 at the ink tank unit-200 side to prevent the inktank unit 200 from being erroneously set is provided for a portion abovethe joint pipe 180 on the face.

An atmospheric air communication port (atmospheric air communicationportion) 115 for communicating the inside of the negative pressurecontrol chamber container 110 with outside air, in this case, theabsorption body 130 stored in the negative pressure control chambercontainer 110 with outside air is formed on the negative pressurecontrol chamber lid 120 and a buffer space 116 comprising a space formedby a rib protruded from the face of the negative pressure controlchamber lid 120 at the absorption body-130 side and an area in which ink(liquid) in an absorption body is absent is provided nearby theatmospheric air communication portion 115.

A valve-operating mechanism is set in the joint port 230, which isconstituted of a first valve frame 260 a, a second valve frame 260 b, avalve element 261, an operculum 262, and an energizing member 263. Thevalve element 261 is slidably supported in the second valve frame 260 band energized to the first valve frame-260 a side by the energizingmember 263. When the joint pipe 180 is not inserted into the joint port230, the margin of the portion of the valve element 261 at the firstvalve frame-260 a side is pressed against the first valve frame 260 aand thereby, the airtightness in the ink tank unit 200 is maintained.

When the joint pipe 180 is inserted into the joint port 230 and thevalve element 261 is pressed by the joint pipe 180 and thereby moves ina direction separate from the first valve frame 260 a, the inside of thejoint pipe 180 communicates with the inside of the ink tank unit 200through an opening formed on the side face of the second valve frame 260b. Thereby, the inside of the ink tank unit 200 is released and the inkin the ink tank unit 200 is supplied into the negative pressure controlchamber unit 100 through the joint port 230 and joint pipe 180. That is,when a valve in the joint port 200 opens, the closed inside of the inkstorage portion of the ink tank unit 200 communicates with the negativepressure control chamber unit 100 only through the opening.

It is preferable to fix the ink-jet head unit 160 and negative pressurecontrol chamber unit 100 to the holder 150 by a method having easydisassembly such as a screw under a state in which the ink-jet head unit160 and negative pressure control chamber unit 100 are fixed to theholder 150 as described for this embodiment because each unit can beremoved and changed in accordance with its durable period.

That is, in case of the ink-jet head cartridge of this embodiment, anink tank for storing different types of inks is not normally erroneouslyset to a negative pressure control chamber by an ID member provided forthe ink tank. However, when an ID member provided for the negativepressure control chamber unit 100 is damaged or a user intentionallysets different types of ink tanks to the negative pressure controlchamber unit 100, it is only necessary to change only the negativepressure control chamber unit 100 immediately after the ink tanks areset to the unit 100. Moreover, when the holder 150 is damaged due to adrop, it is also possible to change only the holder 150.

When separating the negative pressure control chamber unit 100, holder150, and ink-jet head unit 160 including the ink tank unit 200 from eachother, it is preferable to determine the position of a fixed portion sothat it is possible to prevent ink from leaking from each unit.

In the case of this embodiment, the ink tank unit 200 combines with thenegative pressure control chamber unit 100 by using an ink-tank-securingportion 155 of the holder 150. Therefore, only the negative pressurecontrol chamber unit 100 is removed from other fixed unit. That is,unless the ink tank unit 200 is at least removed from the holder 150,the negative pressure control unit 100 is not easily removed from theholder 150. Thus, because the negative pressure control unit 100 isconstituted so as not to be easily removed before the ink tank unit 200is removed from the holder 150, leak of ink from a joint due to the factthat the ink tank unit 200 is carelessly separated from the negativepressure control chamber unit 100 does not occur.

Moreover, because the filter 161 is set to an end of the ink supply pipe165 of the ink-jet head unit 160, ink does not leak from the ink-jethead unit 160 even when the negative pressure control chamber unit 100is separated. Moreover, the negative pressure control chamber unit 100is provided with the buffer space 116 (including an area not holding theink in the absorption bodies 130 and 140) for preventing ink fromleaking from the ink tank and the contact face 113 c is formed betweentwo absorption bodies 130 and 140 having capillary forces different fromeach other (more preferably, a capillary force of a layer nearby thecontact face 113 c including the face 113 c is higher than those ofareas of the absorption bodies 130 and 140). Therefore, the contact face113 c prevents back flow of ink from the absorption body 140 to theabsorption body 130 and thereby, ink hardly leaks from a structureformed by uniting the holder 150, negative pressure control chamber unit100, and ink tank unit 200 into one body even if attitudes of thestructure are changed. Therefore, in case of this embodiment, becausethe ink-jet head unit 160 has a fixed portion on its bottom face servingas a side face of the holder 150 having a connection terminal, it can beeasily separated even while the ink tank unit 200 is set to the holder150.

Moreover, it is permitted that the negative pressure control chamberunit 100 or ink-jet head unit 160 and the holder 150 are united into onebody so that they cannot be separated from each other. To unit them intoone body, it is permitted to use a method for previously uniting theminto one body or thermal caulking so that they cannot be separated fromeach other.

As shown in FIG. 2 and FIGS. 3A and 3B, the ink tank unit 200 isconstituted of an ink container 201, a valve-operating mechanismincluding the first valve frame 260 a and the second valve frame 260 b,and an ID member 250. The ID member 250 prevents the ink tank unit 200and negative pressure control chamber unit 100 from being erroneouslyset.

The valve-operating mechanism controls the flow of ink in the joint port230, which performs opening and closing operations by being engaged withthe joint pipe 180 of the negative pressure control chamber unit 100.Twisting of a valve when set or removed is prevented by a valveconfiguration or a structure for controlling a tank operation range bythe ID member 170 and a concave portion 252 for ID to be describedlater.

<Ink tank unit>

FIGS. 3A and 3B are perspective views for explaining the ink tank unit200 shown in FIG. 2. FIG. 3A is a perspective view showing the ink tankunit 200 and FIG. 3B is a perspective view showing a state in which theink tank unit 200 is disassembled.

Moreover, at the front of the ID member 250 serving as the negativepressure control chamber unit-100 side, a portion above a supply porthole 253 serves as a slope 251. The slope 251 tilts toward the inkstorage 201, that is, backward from the front-end face at the supplyport hole 253-side of the ID member 250. A plurality of concave portions252 (three concave portions in FIG. 3A) for ID for preventing the inktank unit 200 from being erroneously inserted are formed on the slope251. In case of this embodiment, the ID member 250 is set to the front(face having a supply port) of the ink container 201 serving as thenegative pressure control chamber unit-100 side.

The ink container 201 is an almost-polygonal-prismatic hollow containerhaving a negative pressure generation function. The ink container 201 isconstituted of a housing 210 and an inner bag (liquid storage portion)220 (refer to FIG. 2), in which the housing 210 can be separated fromthe inner bag 220. The inner bag 220 is flexible and can be deformed asthe stored ink is discharged. Moreover, the inner bag 220 has apinch-off portion (welding portion) 221 which supports the bag 220 so asto engage with the housing 210. Furthermore, an outside-aircommunication port 222 is formed on a portion nearby the pinch-offportion 221 of the housing 210 so that atmospheric air can be introducedbetween the inner bag 220 and the housing 210 through the outside-aircommunication port 222.

The inner bag 220 comprises three layers such as a liquid contact layerhaving an ink resistance, an elasticity control layer, and gas barrierlayer superior in gas barrier property which are superposed from theinside in the order mentioned, and the layers are functionally separatedfrom each other while connected. The elasticity of the elasticitycontrol layer is kept almost constant in an ink-storage-containeroperating temperature range. That is, the elasticity of the inner bag iskept almost constant by the elasticity control layer in theink-storage-container operating temperature range. In case of the innerbag, it is permitted that an intermediate layer is replaced with anoutside layer, that is, the elasticity control layer serves as anoutermost layer and the gas barrier layer serves as an intermediatelayer.

Because the inner bag is constituted as described above, the inner bagcan completely exhibit functions of the ink-resistant layer, elasticitycontrol layer, and gas barrier layer and the influence of the elasticityof the inner bag on a temperature change decreases. Moreover, because anelasticity suitable to control a negative pressure in the ink containerin an operating temperature range is secured in the inner bag, the innerbag has a buffer function to be described later for the ink in the inkcontainer and negative pressure control chamber unit. (Details will bedescribed later.) Therefore, because it is possible to decrease a bufferchamber formed at the upper portion in the negative pressure controlchamber container, that is, a portion not filled with ink absorptionbodies and an area in which the ink in the absorption bodies 130 and 140is not present, it is possible to downsize the negative pressure controlchamber unit 100 and thereby, realize an ink-jet head cartridge 70having a high use efficiency.

In case of this embodiment, polypropylene is used as a material of aninnermost liquid contact layer constituting the inner bag 220,cyclic-olefin copolymer is used as a material of the intermediateelasticity control layer, and (EVOH saponified EVA(ethylene-vinyl-acetate copolymer resin)) is used as a material of theoutermost gas barrier layer. In this case, impregnating the elasticitycontrol layer with a functional adhesive resin is preferable because itis unnecessary to particularly form an adhesive layer between the layersand thereby, it is possible to decrease the thickness of the inner bag220.

The material of the housing 210 uses polypropylene that is also used forthe innermost layer of the inner bag 220. Moreover, the material of thefirst valve frame 260 a uses polypropylene.

The ID member 250 has a plurality of concave portions 252 for IDprovided for right and left to correspond to a plurality of ID members170 for preventing the ink tank unit 200 from being erroneously set andis fixed to the ink container 201.

An erroneous-setting preventive function obtained by the ID members 170and the concave portions 252 for ID corresponds to a plurality of IDmembers 170 provided for the negative pressure control chamber unit-100side and the concave portions 252 for ID are formed on the ID member250, and thereby an erroneous-setting preventive mechanism isconstituted. Therefore, various ID functions can be executed by changingshapes or positions of the ID member 170 and concave portion 252 for ID.

The concave portion 252 for ID of the ID member 250 and the joint port230 of the first valve frame 260 a are located at the front in thesetting/removing direction of the ink tank unit 200 and formed on the IDmember 250 and first valve frame 260 a.

Moreover, it is possible to accurately mold a valve member and theconcave portion 252 for ID by forming the ink container 201 through blowmolding and the ID member 250 and first valve frame 260 a throughinjection molding and constituting the ink tank unit 200 of threemembers.

When directly forming the concave portion 252 for ID on the inkcontainer 201 serving as a blow tank formed through blow molding, thismay influence separation of the inner bag 220 from an inner layer of theink container 201, that is, may influence a negative pressure generatedin the ink tank unit 200. However, by using a member different from theink container 201 for the ID member 250 serving as an ID portion asshown for the configuration of the ink tank unit 200 of this embodiment,the above influence caused by setting the ID member 250 to the inkcontainer 201 is not applied to the ink container 201. Therefore, it ispossible to stably generate and control a negative pressure in the inkcontainer 201.

The first valve frame 260 a is connected to each of the housing 210 andinner bag 220 of the ink container 201. The first valve frame 260 a isconnected to the inner bag 220 by welding an inner-bag exposure portion221 a serving as an ink discharge portion of the ink container 201 witha face to which a portion of the joint port 230 corresponds. In thiscase, because the housing 210 is made of polypropylene same as theinnermost layer of the inner bag 220, it is possible to weld the firstvalve frame 260 a with the housing 210 even around the joint port 230.

Thereby, a positional accuracy by welding is improved, the supply portof the ink container 201 is completely sealed, and ink is prevented fromleaking from the sealed portion between the first valve frame 260 a andthe ink container 201 when setting or removing the ink tank unit 200. Toperform connection through welding like the case of the ink tank unit200 of this embodiment, it is preferable that the material of a layerserving as a bonding face of the inner bag 220 is the same as that ofthe first valve frame 260 a in order to improve the sealing performance.

Moreover, in case of connection between the housing 210 and the IDmember 250, a face of the first valve frame 260 a facing a sealed face102 connected with the ink container 201, a click portion 250 a formedat the lower portion of the ID member 250, an engagement portion 210 aat the side face of the housing 210, and a click portion 250 a at the IDmember-250 side corresponding to the portion 210 a are engaged eachother and thereby, the ID member is engagement-fixed to the inkcontainer 201.

For the above engagement-fixing, it is preferable to form a structurehaving easy disassembly according to engagement or fitting byirregularity. Thus, by engagement-fixing the ID member 250 to the inkcontainer 201, they are slightly movable. Thereby, it is possible toabsorb a force due to the contact between the ID member 170 and theconcave portion 252 for ID at the time of setting/removing and preventthe ink tank unit 200 and negative pressure control chamber unit 100from damaging.

Moreover, by making the ID member 250 locally engage with the inkcontainer 201 so as to be almost fixed, the ink tank unit 200 can beeasily disassembled and there is an advantage from the viewpoint ofrecycling. Thus, by forming a concave portion serving as the engagementportion 210 a on the side face of the housing 210, the configuration ofthe ink container 201 is simplified when forming the container 201through blow molding, a mold member for molding is also simplified, andcontrol of a film thickness is simplified.

Moreover, the housing 210 is connected with the ID member 250 whileconnecting the first valve frame 260 a to the housing 210 and the clickportion 250 a is engaged with the engagement portion 210 a while holdingthe first valve frame 260 a around the joint port 230. Therefore, it ispossible to improve the strength of the ink tank unit 200, particularlythe joint portion of the unit 200 when setting or removing the unit 200.

Furthermore, in the case of the ink container 201, the portion coveredwith the ID member 250 is concave and the supply port is protruded.Therefore, by fixing the ID member 250 to the ink container 201, it ispossible to eliminate the protrusion at the front of the ink tank unit200. Moreover, it is permitted that the concavo-convex relation betweenthe engagement portion 210 a of the housing 210 and the click portion250 a of the ID member 250 corresponding to the portion 210 a isreverse.

Furthermore, it is possible to control positions of the ink container201 and the ID member 250 in longitudinal and transverse directions. Amethod for connecting the ink container 201 with the ID member 250 isnot restricted to the above mentioned. An engagement-position fixingmethod can use other means.

As shown in FIG. 2, the bottom of the ink container 201 tilts in adirection in which the bottom can be raised and the bottom of a portionof the ink container 201 opposite to the joint port 230-side engageswith the ink-tank securing portion 155 of the holder 150. When removingthe ink tank unit 200 from the holder 150, the engagement portion withthe ink-tank securing portion 155 of the ink container 201 is raised.Therefore, the ink tank unit 200 almost rotates when setting or removingthe unit 200. In case of this embodiment, the rotation center is locatedalmost at the supply port (joint port 230). Strictly saying, however,the rotation center changes. When setting or removing the ink tank unit200 almost through the rotation, a twist more frequently occurs betweenthe ink tank unit 200 and the ink-tank securing portion 155 as thedistance from the fulcrum of rotation up to a corner of the ink-tanksecuring portion 155 of the ink tank unit 200 becomes longer than thedistance from the fulcrum up to the ink-tank securing portion 155 and atrouble may occur that an unnecessary force is generated in setting or apressed portion of the ink tank unit 200 or holder 150 is deformed.

Because the bottom of the ink container 201 of this embodiment is tiltedand the lower end of the portion serving as the ink-tank securingportion-155 side of the ink container 201 is raised, it is possible toprevent an excessive twist due to rotation of the ink tank unit 200 atengagement portions of the ink tank unit 200 and holder 150 and thereby,smoothly set or remove the ink tank unit 200.

In case of the ink-jet head cartridge of this embodiment, the joint port230 is formed at the lower portion of one side face of the ink container201 serving as a face of the negative pressure control chamber unit-100side and a lower portion of other side face of the ink container 201serving as a face opposite to the joint port-230 side, that is, alower-side portion of the rear end engages with the ink-tank securingportion 155. Moreover, the upper portion of the ink-tank securingportion 155 extends upward from the bottom of the holder 150 up to aheight almost equal to the center height 603 of the joint port 230.Thereby, horizontal movement of the joint port 230 is securelycontrolled by the ink-tank securing portion 155 and it is possible topreferably keep the connection state between the joint port 230 and thejoint pipe 180. In this case, to securely keep the connection betweenthe joint port 230 and the joint pipe 180 when the ink tank unit 200 isset, the upper end of the ink-tank securing portion 155 is set to aheight almost equal to the upper portion of the joint port 230.Moreover, the ink tank unit 200 is removably set to the holder 150 dueto the rotation of the unit 200 about a part of the front of the unit200 at the joint port-230 side. When setting or removing the ink tankunit 200, a portion of the unit 200 contacting the negative pressurecontrol chamber unit 100 serves as the rotation center of the ink tankunit 200. Thus, because the bottom of the rear end of the ink container201 tilts as described above, it is possible to decrease the differencebetween the distance from a rotation center 600 up to an upper end 601of the ink-tank securing portion and the distance from the rotationcenter 600 up to a lower end 602 of the ink-tank securing portion.Therefore, it is possible to prevent an excessive twist due to rotationof the ink tank unit 200 at engagement portions of the ink tank unit 200and holder 150 and smoothly set or remove the ink tank unit 200.

Because the ink container 201 and holder 150 are formed into the aboveshapes, it is possible to decrease a twist area between the lowerportion of the rear end of the ink container 201 and the ink-tanksecuring portion 155 when setting or removing the ink tank unit 200 alsowhen increasing the size of the joint port 230 in order to supply ink ata high flow rate. Thereby, it is possible to avoid an unnecessary twistwith the ink-tank securing portion 155 while securing the fixingproperty when setting the ink tank unit 200 to the holder 150.

In this case, if the distance from the rotation center 600 in setting orremoving the ink tank unit 200 up to the lower end 602 of the ink-tanksecuring portion of the ink tank unit 200 excessively increases comparedto the distance from the rotation center 600 up to the upper end 601 ofthe ink-tank securing portion, a force necessary for the setting orremoving operation greatly increases and thereby, the upper end 601 ofthe ink-tank securing portion may be shaved or the ink container 201 maybe deformed. Therefore, it is preferable that the difference between thedistance from the rotation center 600 of the ink tank unit 200 up to thelower end 602 of the ink-tank securing portion of the ink tank unit 200and the distance from the rotation center 600 up to the upper end 601 ofthe ink-tank securing portion is as small as possible in a rangesuperior in setting/removing performance while exhibiting a properfixing force.

Moreover, when the rotation center 600 of the ink tank unit 200 ispresent at a position lower than the center of the joint port 230, thedistance from the rotation center 600 of the ink tank unit 200 up to theupper end 601 of the ink-tank securing portion becomes longer than thedistance from the rotation center 600 up to the lower end 602 of theink-tank securing portion and thereby, it is difficult to accuratelycontrol the ink container 201 at the height of the center of joint port230. Therefore, to accurately fix the height-directional center of thejoint port 230, it is preferable that the rotation center 600 of the inktank unit 200 is present at a position upper than the height-directionalcenter of the joint port 230.

Moreover, when raising the rotation center 600 of the ink tank unit 200up to a position higher than the center height 603 of the joint port230, the thickness of a portion of the ink tank unit 200 contacting theink-tank securing portion 155 increases and a portion contacting theink-tank securing portion 155 increases and thereby, the ink tank unit200 and holder 150 may be easily damaged. Therefore, it is preferablethat the rotation center 600 of the ink tank unit 200 is closer to theheight-directional center of the joint port 230 from the viewpoint ofthe setting/removing performance of the ink tank unit 200. Moreover, itis permitted to properly determine the height of the ink-tank securingportion 155 of the ink tank unit 200 in accordance with thesetting/removing performance of the ink tank unit 200. However, whensetting the portion 155 to a position higher than the rotation center600, the contact distance between the securing portions of the ink tankunit 200 and holder 150 increases and the number of portions rubbed dueto setting/removing operation increases. Therefore, when consideringdeterioration of the ink tank unit 200 and holder 150, it is preferablethat the portion 155 is lower than the rotation center 600 of the inktank unit 200.

Moreover, in case of the ink-jet head cartridge of this embodiment, anenergizing force for fixing a horizontal position of the ink container201 is obtained from a force by the energizing member 263 for energizingthe valve element 216 and a repulsion of a rubber joint portion 280(refer to FIGS. 4A to 4D). Instead of the above mentioned, however, itis also permitted to set a securing portion to the rear end of the inkcontainer 201, or to set energizing means for fixing ahorizontal-directional position of the ink container 201 to the face ofthe ink-tank securing portion 155 at the ink container-201 side or tothe negative pressure control chamber unit 100, or the like. The rubberjoint portion 280 is press-fitted by wall surfaces of a negativepressure control chamber and an ink tank while an ink container isconnected to secure the airtightness (it is enough to decrease thenumber of areas exposed to the atmospheric air even if completeairtightness cannot be kept) of a combined portion (periphery of jointpipe) and moreover functions as an auxiliary of a seal by a sealingprotrusion to be described later.

Then, the internal configuration of the negative pressure controlchamber unit 100 will be described below.

A member in which the absorption body 130 is superposed on theabsorption body 140 to generate a negative pressure is stored in thenegative pressure control chamber unit 100. Therefore, the absorptionbody 130 communicates with the atmospheric air communication portion 115and the absorption body 140 closely contacts with the absorption body130 at its upper side and closely contacts with the filter 161 at itslower side. The contact face 113 c between the absorption bodies 130 and140 is lower than the lower end of the joint pipe 180 serving as acommunication portion under the operating attitude.

The absorption bodies 130 and 140 are made of fiber bodies in whichfibers are almost oriented in the same direction and the main fiberdirection tilts from the vertical direction (more preferably, so thatthe direction becomes almost horizontal like the case of thisembodiment) while the ink-jet head cartridge 70 is mounted on a printerand stored in the negative pressure control chamber container 110.

The absorption bodies 130 and 140 in which fibers are oriented in thesame direction are manufactured by using short fibers (having a lengthof approx. 60 mm and comprising mixed fibers of polypropylene andpolyethylene) made of thermoplastic resin crimped as fibers andarranging directions of short fibers in a fiber group with a cardingmachine, then heating the fibers (it is preferable to set the heatingtemperature to a value higher than the melting point of polyethylenehaving a relatively-low melting point and lower than the melting pointof polypropylene having a relatively-high melting point), and cuttingthe fibers into a desired length. In case of the fiber member of thisembodiment, directions of fibers of the surface layer are arrangedcompared to those of fibers of the middle portion and a capillary forceto be generated is larger than that of the middle portion. However, thesurface of the fiber member is not a mirror surface but it has a slightirregularity mainly generated when bundling slivers andthree-dimensionally has welded intersections even at the surface layer.Therefore, in the case of the contact face 113 c between the absorptionbodies 130 and 140 in which fiber directions are arranged, surfaceshaving irregularity contact each other and thereby, ink has a properflowability in the horizontal direction as a whole together with surfaceareas of the absorption bodies 130 and 140 nearby the contact face 113c. That is, only the contact face 113 c is particularly superior in inkflowability compared to surrounding areas and thereby, an ink path isnot formed between the gap between the negative pressure control chambercontainer 110 and absorption bodies 130 and 140 and the contact face 113c. Therefore, by forming the contact face 113 c between the absorptionbodies 130 and 140, it is prevented that a part of the interface betweenink and gas (gas-liquid interface) moves below the contact face 113 c inthe absorption bodies 130 and 140 and it is possible to stabilize thegas-liquid interface. Thus, it is possible to stabilize a staticnegative pressure at a head portion currently supplying ink.

Moreover, as shown in FIG. 7, when noticing the directional property ofa fiber member, fibers are continuously arrayed mainly in a longitudinaldirection F1 arranged by a carding machine and the fiber member has astructure in which fibers are connected each other because some ofintersections between the fibers are welded due to thermal molding in adirection F2 perpendicular to the direction F1. Therefore, theabsorption bodies 130 and 140 are not easily broken even if applying atension in the direction F1 in FIG. 7. However, when pulling the bodies130 and 140 in the direction F2 in FIG. 7, joints between fibers arebroken and the fibers can be easily separated from each other comparedto the case of the direction F1.

Because the main fiber direction F1 is present in the absorption bodies130 and 140 made of fibers, the main fiber direction F1 and the fiberdirection F2 perpendicular to the direction F1 are different from eachother in ink flowability and holding way under a stationary state.

Internal structures of the absorption bodies 130 and 140 will be moreminutely described below. Crimped short fibers shown in FIG. 8A areheated when some fiber directions are arranged and thereby, result inthe state shown in FIG. 8B. In this case, an area (in which a pluralityof short fibers are overlapped in fiber directions in FIG. 8A has a highprobability in which intersections are welded as shown in FIG. 8B andresultantly, continuous fibers not easily cut in the direction F1 shownin FIG. 7 are formed in fiber directions. Moreover, by using crimpedsort fibers, end areas of short fibers (β and γ shown in FIG. 8A) arethree-dimensionally welded with other short fiber (β) or directly remainas an end (γ). Moreover, because not all fibers are arranged in thecompletely same direction, the short fiber (ε shown in FIG. 8A) tiltingand contacting from the beginning with another short fiber so as tointersect with it is directly welded after heated (ε shown in FIG. 8B).Thus, fibers having a high strength compared to that of a conventionalunidirectional fiber bundle are also formed in the direction F2.

Moreover, in case of this embodiment, the absorption bodies 130 and 140are arranged so that the fiber direction F1 becomes almost horizontaland almost parallel with the direction toward an ink supply port from acommunication portion. Therefore, as shown in FIG. 6, the gas-liquidinterface L (interface between ink and gas) in the absorption body 140has an almost horizontal direction parallel with the main fiberdirection F1 while the ink container 201 is connected. Therefore, evenif fluctuation due to an environmental change occurs, the gas-liquidinterface maintains an almost horizontal direction. Therefore, whenenvironmental fluctuation ends, the gas-liquid interface returns to theoriginal position of the gas-liquid interface L but the fluctuation tothe gravitational direction of the gas-liquid interface does notincrease correspondingly to the number of cycles of environmentalchanges.

As a result, when the ink in the ink container 201 is completelyconsumed to change the ink tank unit to the new ink tank unit 200, thegas-liquid interface is kept almost horizontal. Therefore, even if thechange frequency of the ink tank unit 200 increases, the buffer space116 does not decrease.

Thus, to stabilize the position of the gas-liquid interface L undergas-liquid change independently of an environmental change, it ispreferable to form a layer having a main fiber array component in almosthorizontal direction in an area of the upper end of a communicationportion (joint pipe 180 in the case of this embodiment) serving as ajoint, more preferably in an area including a portion upper than theupper end. From another viewpoint, it is preferable that the layer ispresent in an area connecting the supply port 131 with the upper end ofthe communication portion. From still another viewpoint, it ispreferable that the area is present on gas-liquid interface undergas-liquid change operation. When functionally capturing the latter, afiber layer having the directional property of the above array makes thegas-liquid interface in the absorption body 140 horizontal under theliquid supply operation due to gas-liquid change and has a function forcontrolling a vertical-directional change of the absorption body 140 dueto movement of liquid from the ink container 201.

By forming the above layer in the absorption body 140, the gas-liquidinterface L can control the fluctuation to the gravitational direction.In this case, it is preferable that the main fiber array component isalso almost parallel in the longitudinal direction at ahorizontal-directional cross section of the absorption body 140 becausethe longitudinal direction of fibers can be effectively used.

In this case, if the fiber array direction even slightly tilts from thevertical direction, the above effect is theoretically obtained. However,when the fiber array direction is practically kept in a range of ±30°from the horizontal direction, a clear effect can be confirmed.Therefore, the term “almost” of almost horizontal includes the abovetilt in this specification.

In the case of this embodiment, the main fiber direction array componentis similarly constituted also in an area lower than the upper end of thecommunication portion because the component is constituted of the sameabsorption body 140. Therefore, in the case of the gas-liquid changeoperation shown in FIG. 6, the gas-liquid interface L does notcarelessly fluctuate in an area lower than the upper end of thecommunication portion. Therefore, an ink supply trouble such as inkshortage does not occur.

That is, in the gas-liquid change operation, when the atmospheric airintroduced through the atmospheric air communication port 115 reachesthe gas-liquid interface L, it is dispersed along the main fiberdirection. As a result, an interface under the gas-liquid changeoperation is kept almost horizontal and can be stabilized. Thus, anadvantage can be obtained that it is possible to more securely supplyink while keeping a stable negative pressure. Moreover, the main fiberdirection is almost horizontal also for the gas-liquid change operationin the case of this embodiment. Therefore, ink is almost uniformlyconsumed in the horizontal direction. As a result, it is possible toapply an ink supply method for decreasing residual ink also to the inkin the negative pressure control chamber container 110. Therefore, inthe case of a system in which the ink tank unit 200 for directly storinga liquid can be changed as described for this embodiment, it is possibleto effectively form an area not storing the ink in the absorption bodies130 and 140. Therefore, the buffer space efficiency is improved and itis possible to provide an ink supply method strong in environmentalfluctuation.

Moreover, when the ink-jet head cartridge of this embodiment uses acartridge to be mounted on the so-called serial-type printer, it is setto a carriage to be reciprocally scanned. In this case, a force of acarriage-moving-directional component works on the ink in the ink-jethead cartridge in accordance with the reciprocal motion of the carriage.To minimize bad influences of the above force on ink supplycharacteristics from the ink tank unit 200 to the ink-jet head unit 160,it is preferable that the fiber direction of the absorption bodies 130and 140 and the array direction of the ink tank unit 200 and negativepressure control chamber unit 100 are set to a direction toward thesupply port 131 of the negative pressure control chamber container 110from the joint port 230 of the ink tank unit 200.

<Tank setting operations>

Then, operations for setting the ink tank unit 200 to a united body ofthe negative pressure control chamber unit 100 and holder 150 will bedescribed below by referring to FIGS. 4A to 4D.

FIGS. 4A to 4D are sectional views for explaining operations for settingthe ink tank unit 200 to the holder 150 to which the negative pressurecontrol chamber unit 100 is set. The ink tank unit 200 is set by almostrotating it in directions of the arrows F and G along itswidth-directional guide (not illustrated), the bottom 151 of the holder150, and a guide portion 121 provided for the negative pressure controlchamber lid 120 of the negative pressure control chamber unit 100, andthe ink-tank securing portion 155 at the rear of the holder 150.

First, as the operation for setting the ink tank unit 200, the ink tankunit 200 is moved up to the position shown in FIG. 4A, that is, theposition where the slope 251 of the ink tank unit 200 contacts the IDmember 170 for preventing the ink tank unit provided for the negativepressure control chamber unit 100 from being erroneously inserted. Atthis point of time, the joint port 230 does not contact with the joinpipe 180. However, if an erroneous ink tank unit 200 is set at the abovepoint of time, the slope 251 interferes with the ID member 170 and thesubsequent operations for setting the ink tank unit 200 are prevented.Because the ink-jet head cartridge 70 is constituted as described above,the joint port 230 does to contact with the joint pipe 180 as describedabove. Therefore, it is possible to prevent unnecessary change of headsor ink tanks of an ink-tank-change-type apparatus due to mixing of inksat a joint portion at the time of erroneous setting, fixing of ink (acase is also considered in which fixing is caused by the absorptionbodies 130 and 140 depending on an ink component (e.g. reaction ofanions and cations), so that the negative pressure control chamber unit100 cannot be used), or the like. Moreover, by the ID portion of the IDmember 250 on a slope as described above and thereby almostsimultaneously inserting a plurality of ID members 170 into theircorresponding concave portions for ID, it is possible to confirm IDs andachieve a secure erroneous-setting-preventive function.

Then, as shown in FIG. 4B, the ink tank unit 200 is moved toward thenegative pressure control chamber unit 100 so that the member 170 for IDis inserted into the concave portion 252 for ID and the joint pipe 180is inserted into the joint port 230.

Then, because the ink tank unit 200 set to a predetermined position isprovided for the position shown in FIG. 4C, that is, the position wherethe ID member 170 corresponds to the concave portion 252 for ID, it isfurther moved up to the inner part of the negative pressure controlchamber unit-200 side. Moreover, when the ink tank unit 200 is rotatedin the direction of the arrow G, the front end of the joint pipe 180contacts the valve element 261 and the valve element 261 is pushed.Thereby, a valve-operating mechanism opens, the inside of the ink tankunit 200 is communicated with the inside of the negative pressurecontrol chamber unit 100, and ink 300 in the ink tank unit 200 can besupplied into the negative pressure control chamber unit 100. Details ofthe opening/closing operation of the valve-operating mechanism will bedescribed later.

Thereafter, the ink tank unit 200 is further rotated in the direction ofthe arrow G and inserted into the position shown in FIG. 2. Thereby, therear lower portion of the ink tank unit 200 is secured to theink-tank-securing portion 155 of the holder 150 and thus, the ink tankunit 200 is fixed to a desired position. Under such a state, the IDmember 170 moves in a direction slightly separate from the concaveportion 252 for ID. The backward (holder securing portion-155 side)energizing force for fixing the ink tank unit 200 is generated by theenergizing member 263 in the ink tank unit 200 and the rubber jointportion 280 provided around the joint pipe 180.

As described above, because the concave portion 252 for ID is formed onthe slope 251 in the ink tank unit 200 and moreover, the lower face ofthe ink tank unit 200 tilts, and thereby it is possible to securely setor remove the ink tank unit 200 in a minimum space without causing anyerroneous setting or color mixing.

Thus, at the time of connecting the ink tank unit 200 with the negativepressure control chamber unit 100, ink moves until the pressure in thenegative pressure control chamber unit 100 becomes equal to the pressurein the ink container 201 and as shown in FIG. 4D, an equilibrium state(referred to as a use start state) is realized while the pressure in thejoint pipe 180 and that in the joint port 230 are negative.

Therefore, ink movement for the above equilibrium state to be realizedwill be described below in detail.

When the ink tank unit 200 is set and thereby, the valve-operatingmechanism provided for the joint port 230 of the ink container 201opens, the ink storage portion is substantially closed except the jointport 230. Then, the ink in the ink container 201 flows to the joint port230 and an ink path is formed between the joint port 230 and theabsorption body 140 of the negative pressure control chamber unit 100.When the ink path is formed, ink movement from the ink container 201 tothe absorption body 140 is started due to a capillary force of theabsorption body 140 and as a result, the interface of the ink in theabsorption body 140 rises. Moreover, the inner bag 220 startsdeformation with the central portion of a face having the maximum areaso that the volume in the inner bag 220 decreases.

In this case, the housing 210 works so as to control displacements ofcorners of the inner bag 220. Therefore, an acting force of deformationdue to ink consumption and an acting force for returning to the statebefore the inner bag 220 is set (an initial state shown in FIGS. 4A to4C of this embodiment) are applied to the inner bag 220 to generate anegative pressure corresponding to a degree of deformation withoutsudden change. Because the space between the housing 210 and the innerbag 220 communicates with outside air through the outside-aircommunication port 222, air is introduced between the housing 210 andthe inner bag 220 in accordance with the above deformation.

However, even if air is present in the joint port 230 and joint pipe180, the air easily moves into the inner bag 220 because the inner bag220 is deformed due to discharge of ink when the ink in the inkcontainer 201 contacts the absorption body 140 and thereby, an ink pathis formed.

Ink movement continues until the static negative pressure in the jointport 230 of the ink container 201 becomes equal to the static negativepressure in the joint pipe 180 of the negative pressure control chamberunit 100.

As described above, movement of ink from the ink container 201 to thenegative pressure control chamber unit 100, when the ink container 201is connected with the negative pressure control chamber unit 100, isperformed without introducing any gas into the ink container 201 throughthe absorption bodies 130 and 140. It is permitted to set the staticnegative pressure of each chamber when an equilibrium state is realizedto a proper value in accordance with the type of liquid dischargerecording means to be connected so that ink does not leak from liquiddischarge recording means such as the ink-jet head unit 160 or the likeconnected to the ink supply port of the negative pressure controlchamber unit 100.

Moreover, because an ink quantity held by the absorption body 130 beforeconnection fluctuates, an area in which the absorption body 140 is notfilled with ink may be left even when an equilibrium state is realized.This area can be used as a buffer area

On the contrary, when it is feared that pressures in the joint pipe 180and joint port 230 under an equilibrium state may become positive, it ispermitted to perform attraction recovery by the attraction recoverymeans to be mentioned later provided for a liquid discharge recorder andthereby slightly discharge ink.

As described above, the ink tank unit 200 of this embodiment is set tothe holder 150 almost in accordance with the almost rotating operationin which the unit 200 is diagonally inserted while putting the outerbottom of the unit 200 on the ink-tank securing portion 155 of theholder 150 and inserted into the bottom of the holder 150 after gettingover the ink-tank securing portion 155. Moreover, the ink tank unit 200is taken out of the holder 150 by reversing the above operation. Then,the valve-operating mechanism provided for the ink tank unit 200 isopened or closed in accordance with setting or removing of the ink tankunit 200.

<Opening/closing operation of valve-operating mechanism>

Opening/closing operation of a valve-operating mechanism will bedescribed below by referring to FIGS. 5A to 5E.

FIG. 5A shows a state just before the ink tank unit 200 is diagonallyinserted into the holder 150 by turning the joint port 230 diagonallydownward and the joint pipe 180 is inserted into the joint port 230.

In this case, a sealing protrusion 180 a is integrally set over thewhole outer periphery of the joint pipe 180 and a valve-opening/closingprotrusion 180 b is set to the front end of the pipe 180. The sealingprotrusion 180 a contacts a joint sealing face 260 of the joint port 230when the joint pipe 180 is inserted into the joint port 230, which isdiagonally set so that the distance from the front end of the joint pipe180 at the upper end becomes larger than that at the lower end.

Because the sealing protrusion 180 a slides on the joint sealing face260 at the time of setting or removing the ink tank unit 200 asdescribed later, it is preferable to use a material having a highsliding property and a high adhering property with the joint sealingface 260 for the sealing protrusion 180 a. Moreover, the form of theenergizing member 263 for energizing the valve element 261 toward thefirst valve frame 260 a is not specifically restricted. It is possibleto use a spring member such as a coil spring or flat spring or aflexible member such as rubber. Furthermore, at the time of consideringthe recycling property, it is preferable to use an elastic member madeof resin.

Under the state shown in FIG. 5A, the valve opening/closing protrusion180 b does not contact the valve element 261 but a sealing portionformed on the outer periphery of the end of the valve element 261 at thejoint pipe-180 side is pressed against the sealing portion of the firstvalve frame 260 a by the energizing force of the energizing member 263.Thereby, the airtightness in the ink tank unit 200 is maintained.

By further inserting the ink tank unit 200 into the holder 150, thejoint sealing face 260 of the joint port 230 is sealed by the sealingprotrusion 180 a. In this case, because the sealing protrusion 180 a isdiagonally set as described above, the lower end of the sealingprotrusion 180 a first contacts the joint sealing face 260, the contactrange between the lower end and the joint sealing face 260 slowlyexpands toward the upper portion of the sealing protrusion 180 a whilethe lower end slides on the joint sealing face 260 because the ink tankunit 200 is inserted as shown in FIG. 5B, and finally the upper end ofthe sealing protrusion 180 a contacts the joint sealing face 260 asshown in FIG. 5C. Thereby, the overall circumference of the sealingprotrusion 180 a contacts the joint sealing face 260 and the joint port230 is sealed by the sealing protrusion 180 a.

Moreover, under the state shown in FIG. 5C, the valve opening/closingprotrusion 180 b does not contact the valve element 261 and thus, thevalve-operating mechanism does not open. Therefore, because the jointport 230 is sealed before the valve-operating mechanism opens, it ispossible to prevent ink from leaking from the joint port 230 while theink tank unit 200 is set.

Furthermore, because the joint port 230 is slowly sealed from the lowerside of the joint sealing face 260 as described above, the air in thejoint port 230 is exhausted from the gap between the sealing protrusion180 a and the joint sealing face 260 before the joint port 230 is sealedby the sealing protrusion 180 a. Thus, because the air is exhausted fromthe joint port 230, the quantity of the air remaining in the joint port230 is minimized while the joint port 230 is sealed and excessivecompression of the air in the joint port 230 due to insertion of thejoint pipe 180 into the joint port 230, that is, excessive rise of thepressure in the joint port 230 is prevented. As a result, it is possibleto prevent the valve from being carelessly opened due to a pressure risein the joint port 230 and ink from entering the joint port 230 due tocareless opening of the valve.

By further inserting the ink tank unit 200, the valve opening/closingprotrusion 180 b pushes the valve element 261 against the energizingforce of the energizing member 263 while the joint port 230 is sealed bythe sealing protrusion 180 a. Thereby, an opening 260 c of the secondvalve frame 260 b communicates with the joint port 230, the air in thejoint port 230 is introduced into the ink tank unit 200 after passingthrough the opening 260 c, the ink in the ink tank unit 200 is suppliedto the negative pressure control chamber container 110 (refer to FIG. 2)after passing through the opening 260 c and joint pipe 180.

Thus, because the air in the joint port 230 is introduced into the inktank unit 200, a negative pressure in the inner bag 220 (refer to FIG.2) is moderated, for example, at the time of resetting the ink tank unit200 currently used. Therefore, the balance between negative pressures ofthe negative pressure control chamber container 110 and inner bag 220 isimproved and it is possible to prevent the resupply performance of inkto the negative pressure control chamber container 110 fromdeteriorating.

After the above operations, by inserting the ink tank unit 200 into thebottom of the holder 150 and setting the ink tank unit 200 to the holder150 as shown in FIG. 5E, the joint port 230 and joint pipe 180 arecompletely connected each other and a state is ready in which theabove-described gas-liquid change is securely performed.

In case of this embodiment, the opening 260 c is set to the second valveframe 260 b nearby a valve-frame sealing portion 264 at the bottom sideof an ink tank. According to the configuration of this opening 260 c,when the valve-operating mechanism opens, that is, the valve element 261is pressed by the valve opening/closing protrusion 180 b and immediatelyafter the element 261 is moved toward the valve lid 262, supply of theink in the ink tank unit 200 to the negative pressure control chamberunit 100 is started and it is possible to minimize the quantity of inkremaining in an ink tank when ink is consumed.

Moreover, in case of this embodiment, elastomer is used as a materialfor configuring the joint sealing face 260 of the first valve frame 260a, that is, the sealing portion of the first valve frame. Thus, by usingthe elastomer as the material, the joint sealing face 260 can secure acertain sealing performance with the sealing protrusion 180 a of thejoint pipe 180 according to the elasticity of the elastomer and thesealing portion of the first valve frame 260 a can secure a certainsealing performance with the sealing portion of the valve element 261.Moreover, the elastomer used as a material can be integrated with thefirst valve frame 260 a and therefore, the above effect can be obtainedwithout increasing any number of components. Furthermore, a portionusing elastomer as a material is not restricted to the aboveconfiguration. It is also permitted to use elastomer as a material ofthe sealing protrusion 180 a formed on the joint pipe 180 or a materialof the sealing portion of the valve element 261.

On the other hand, if the ink tank unit 200 is removed from the holder150, cancel of sealing of the joint port 230 and operations of thevalve-operating mechanism are performed in the sequence reverse to thesequence of the above operations.

That is, by removing the ink tank unit 200 from the holder 150 whilerotating the unit 200 inversely to the direction when setting the unit200, the valve element 261 is first advanced by the energizing force ofthe energizing member 263 and then, the sealing portion of the valveelement 261 is pressed against the sealing portion of the first valveframe 260 a and thereby, the joint port 230 is closed by the valveelement 261.

Thereafter, by further removing the ink tank unit 200, sealing of thejoint port 230 is canceled by the sealing protrusion 180 a. Thus,because sealing of the joint port 230 is canceled after thevalve-operating mechanism is closed, excessive ink is not supplied tothe joint port 230.

Moreover, because the sealing protrusion 180 a is diagonally set asdescribed above, sealing of the joint port 230 is canceled starting withthe upper end of the sealing protrusion 180 a. Before sealing of thejoint port 230 is canceled, ink is left in the joint port 230 and jointpipe 180. However, ink does not leak from the joint port 230 because theupper end of the sealing protrusion 180 a is first released but thelower end of it is still sealed. Moreover, because insides of the jointport 230 and joint pipe 180 are kept at a negative pressure, when theupper end of the sealing protrusion 180 is released, atmospheric airenters the joint port 230 through the upper end and the ink left in thejoint port 230 and joint pipe 180 is attracted into the negativepressure control container 110.

Thus, by releasing the upper end of the sealing protrusion 180 a beforecanceling sealing of the joint port 230 and moving the ink left in thejoint port 230 to the negative pressure control container 110, ink isprevented from leaking from the joint port 230 when removing the inktank unit 200 from the holder 150.

As described above, according to the connection structure between theink tank unit 200 and negative pressure control container 110 of thisembodiment, the joint port 230 is sealed before the valve-operatingmechanism of the ink tank unit 200 operates. Therefore, it is possibleto prevent ink from carelessly leaking from the joint port 230.Moreover, by setting a time difference between sealing timing andsealing cancel timing at the upper portion and lower portion whenconnecting and removing the unit 200, it is possible to prevent acareless operation of the valve element 261 when connecting the ink tankunit 200 and the ink left in the joint port 230 from leaking whenremoving the unit 200.

Moreover, in case of this embodiment, the valve element 261 is set tothe back of the opening end of the joint port 230 and the valve element261 is operated by the valve opening/closing protrusion 180 b at thefront end of the joint pipe 180. Therefore, a user does not directlytouch the valve element 261. Thus, it is possible to prevent the userfrom being contaminated by the ink attached to the valve element 261.

Furthermore, in case of this embodiment, the contact face 113 c betweenthe absorption bodies 130 and 140 is formed below the lower end of thejoint pipe 180. Therefore, as shown in FIG. 12, the gas-liquid interfaceL rises in the absorption body 130 as remaining ink 301 is furtherabsorbed. Therefore, as shown for the conventional example, when thegas-liquid interface L reaches the contact face 113 c between theabsorption bodies 130 and 140, the ink absorption rate is not loweredand therefore, the remaining ink 301 can be smoothly absorbed. Moreover,because the remaining ink is absorbed from the contact face with theupper absorption body 130 having a comparatively-low fiber density and asmall dynamic resistance of ink, the absorption rate increases comparedto the case in which ink is absorbed from the contact face with thelower absorption body 140 having a comparatively-large dynamicresistance of ink. Therefore, because the absorption rate of the ink 301is small, it is possible to prevent the ink from fixing in the jointpipe 180 or splashing outward.

<Relation between setting/removing operation of joint portion and ID>

Then, the relation between setting/removing operation of a joint portionand ID will be described below by referring to FIGS. 4A to 4D and FIGS.5A to 5E. FIGS. 4A to 4D and FIGS. 5A to 5E are illustrations showingthe steps of setting the ink tank unit 200 to the holder 150, in whichFIGS. 4A, 4B, and 4C show states of ID and FIGS. 5A, 5B, and 5C showdetails of the joint portion at the same period.

First, setting operation is performed up to positions shown in FIG. 4Aand FIG. 5A, that is, positions at which a plurality of ID members 170for preventing the ink tank unit 200 provided for the negative pressurecontrol chamber unit 100 from being erroneously inserted contacts theink-tank slope 251. At this point of time, the joint port 230 does notcontact with the joint pipe 180. If an erroneous ink tank unit is set atthis point of time, the slope 251 interferes with the ID member 170 toprevent other ink tank units from being set. According to thisconfiguration as described above, because the joint port 230 does notcontact with the joint pipe 180 at all, it is possible to prevent mixingof various color inks, fixing of ink, or non-discharge of ink at thejoint portion, an image defect, a system trouble, or unnecessary changeof heads of an ink-tank-change-type system when an erroneously ink tankunit is set.

Then, because the ink tank unit 200 set to a correct position is set tothe position shown in FIG. 4B, that is, the position at which the IDmember 170 corresponds to the concave portion 252 for ID, it can befurther inserted up to (the negative pressure control chamber unit-100side). In case of the ink tank unit 200 inserted up to the aboveposition, the joint port 230 and the lower end of the sealing protrusion180 a of the joint pipe 180 contact the sealing face 260 of the jointport 230.

Subsequently, the joint portion is connected in accordance with theabove steps and the inside of the ink tank unit 200 is communicated withthe inside of the negative pressure control chamber unit 100.

In case of the above embodiment, the sealing protrusion 180 a isintegrally provided for the joint pipe 180. However, it is alsopermitted to use a configuration in which the sealing protrusion 180 aand the joint pipe 180 are constituted separately from each other sothat the sealing protrusion 180 a can rotate about the joint pipe 180 bymaking the sealing protrusion 180 a almost engage with a convex orconcave portion formed around the joint pipe 180. However, the movablerange of the sealing protrusion 180 a is designed so that thevalve-element opening/closing protrusion 180 b does not contact thevalve element 261 before the sealing protrusion 180 a in the movablerange completely contacts with the joint sealing face 260 when the inktank 200 is set to the holder 150.

As for the step in which the ink tank unit 200 is set to the holder 150,it is shown in the case of the above embodiment that the lower end ofthe sealing protrusion 180 a contacts the joint sealing face 260, thecontact range between the lower end and the face 260 slowly expandstoward the upper portion of the sealing protrusion 180 while the inktank unit 200 slides on the joint sealing face 260 in accordance withinsertion of the unit 200, and finally the upper end of the sealingprotrusion 180 a contacts the joint sealing face 260. However, it isalso permitted that the upper end of the sealing protrusion 180 acontacts the joint sealing face 260, the contact range between the upperend and the face 260 slowly expands toward the lower portion of thesealing protrusion 180 a while the upper end slides on the joint sealingface 260 in accordance with insertion of the ink tank unit 200, andfinally the lower end of the sealing protrusion 180 a contacts the jointsealing face 260. Moreover, it is permitted that the lower end and theupper end contact at the same time. In this case, even if the airpresent between the joint pipe 180 and the valve element 261 pushes thevalve element 261 and thereby, the valve element 261 opens, the ink 300in the container 201 does not leak out of it because the joint port 230is completely sealed by the sealing protrusion 180 a and joint sealingface 260. That is, it is a point of the present invention that the jointpipe 180 and joint port 230 are completely sealed and thereafter, thevalve-operating mechanism is released. According to the aboveconfiguration, the ink 300 in the ink tank does not leak outward whenthe ink tank unit 200 is set. Moreover, the pushed air enters the inktank unit 200 and pushes out the ink 300 to the joint port 230.Therefore, the ink is quickly supplied to the absorption body 140 fromthe ink container 201.

<Ink supply operation>

Then, the ink supply operation by the ink-jet head cartridge shown inFIG. 2 is described below by referring to FIG. 6. FIG. 6 is a sectionalview for explaining the ink supply operation by the ink-jet headcartridge shown in FIG. 2.

As described above, by diving the absorption body in the negativepressure control chamber unit 100 into a plurality of members, it ispossible to consume the ink in the upper absorption body 130 and thenconsume the ink in the lower absorption body 140 when ink is present inboth the absorption bodies 130 and 140 of the ink-jet head cartridgeshown in FIG. 2. Moreover, when the gas-liquid interface L lowers due toan environmental change or consumption of ink, the ink in the absorptionbody 130 and the ink nearby the contact face 113 c between theabsorption bodies 130 and 140 are initially consumed and then, the inkin the absorption body 140 is consumed. Therefore, a phenomenon hardlyoccurs that a part of the gas-liquid interface L lowers and reaches thesupply port 131 and thereby, ink shortage occurs. Moreover, when thegas-liquid interface L rises due to an environmental change, thegas-liquid interface L rises while keeping a state parallel with thefiber direction of the absorption body 140. Therefore, it is possible tostably secure buffer areas other than the buffer space 116 in thenegative pressure control chamber unit 100. Moreover, as described forthis embodiment, by increasing the capillary force of the absorptionbody 140 compared to the capillary force of the absorption body 130, itis possible to completely consume the ink in the upper absorption body130 under operation.

Furthermore, in the case of this embodiment, the absorption bodies 130and 140 contact each other at the contact face 113 c because theabsorption body 130 is pressed against the absorption body 140 by a ribof the negative pressure control chamber lid 120. Therefore, portionsnearby the contact face 113 c between the absorption bodies 130 and 140have a compression rate and a capillary force higher than those of otherportions. That is, when assuming the capillary of the absorption body140 as P1, the capillary force of the absorption body 130 as P2, and thecapillary force of the contact face 113 c between the absorption bodies130 and 140 and an area (boundary layer) nearby the contact face 113 cas PS, the following expression is obtained: P2<P1<PS. Thus, by formingthe boundary layer having a large capillary force, it is possible tosecurely show the above-mentioned effect because the interface has acapillary force meeting the above condition even if capillary forceranges of P1 and P2 considering the fluctuation of density areoverlapped each other due to the fluctuation of densities in theabsorption bodies 130 and 140. Moreover, as described above, setting thejoint pipe 180 nearby the lower portion of the contact face 113 cbetween the absorption bodies 130 and 140 is preferable because a liquidlevel at the time of gas-liquid change can be stably kept at theposition.

Then, a method for constituting the contact face 113 c of thisembodiment is described below. In case of this embodiment, as thematerial of the absorption body 140 serving as a capillary forcegenerating member, olefin-based resin fiber (2-denier) having acapillary force P1 of −110 mmAq is used and has a hardness of 0.69kgf/mm. In this case, hardnesses of the absorption bodies 130 and 140are obtained by measuring a repulsion when inserting a push rod with adiameter of 15 mm into an absorption body while the bodies 130 and 140are stored in the negative pressure control chamber container 110 andmeasuring a gradient of the repulsion to the insertion value of the pushrod. Moreover, as the material of the absorption body 130, olefin-basedresin fiber same as that of the absorption body 140 is used. However, P2of the absorption body 130 is weak compared to the case of theabsorption body 140 and the capillary force P2 is equal to −80 mmAq, thediameter of the fiber material is thick (6-denier), and the absorptionbody 130 has a high rigidity of 1.88 kgf/mm.

Thus, by making the absorption body 130 having a low capillary forceharder than the absorption body 140 having a high capillary force andbringing them into contact with each other and combining them, theabsorption body 140 is crushed nearby the contact face 113 c between theabsorption bodies 130 and 140 and it is possible to set the capillaryforces so as to meet P2<P1<PS. Moreover, it is possible to make thedifference between P2 and PS equal to or larger than the differencebetween P2 and P1 without fail.

<Ink-jet head cartridge>

FIG. 9 is a schematic illustration of an ink-jet head cartridge using anink tank unit that can be applied to the present invention.

The ink-jet head cartridge 70 having the configuration shown in FIG. 9is provided with a negative pressure control chamber unit 100 in whichnegative pressure control chamber containers 110 a, 110 b, and 110 crespectively storing a liquid are integrated with an ink-jet head unit160 capable of discharging a plurality of liquids (three colors ofyellow (Y), magenta (M), and cyan (C) in the case of this embodiment) sothat ink tank units 200 a, 200 b, and 200 c respectively storing aliquid can be set to or removed from the negative pressure controlchamber unit 100.

To correctly set the ink tank units 200 a, 200 b, and 200 c to theircorresponding negative pressure control chamber containers 110 a, 110 b,and 110 c, this embodiment is constituted so as to securely preventerroneous setting by setting a holder 150 for covering a part of theouter face of the ink tank unit 200, an ID member 250 having a concaveportion at the front of the ink tank unit 200 in the setting direction,and a convex ID member 170 corresponding to the concave portion of theID member 250 to the negative pressure control chamber container 110.

In case of the present invention, it is needless to say that types ofliquids to be stored can use colors other than Y, M, and C and thenumber of liquid containers to be stored and a combination of them (forexample, only black (Bk) is stored in an independent tank and other Y,M, and C are stored in an integrated tank) is optional.

<Recorder>

Finally, an ink-jet recorder on which the above ink tank unit or ink-jethead cartridge can be mounted is described below by referring to FIG.10.

The recorder shown in FIG. 10 comprises a carriage 81 on which an inktank unit 200 and an ink-jet head cartridge 70 can be removably mounted;a head recovery unit 82 in which a head cap for preventing the inkdischarged from a plurality of orifices of a head from drying and anattraction pump for attracting the ink discharged from the orifices whenthe head malfunctions are built; and a sheet supply face 83 to which arecording sheet serving as a recording medium is carried.

The carriage 81 uses a position on the recovery unit 82 as the homeposition, which is scanned leftward in FIG. 10 when a belt 84 is drivenby a motor or the like. During the above scanning, printing is performedby discharging ink toward a recording sheet carried onto the sheetsupply face (platen) 83 from the head.

A valve-operating mechanism of the present invention can be mostpreferably used for the above liquid container. However, the shape ofthe liquid container is not restricted to the above shape. It ispossible to apply the mechanism to other container for directly storingliquid at a supply port.

Second Embodiment

FIG. 13 shows a sectional view of an ink-jet head cartridge of a secondembodiment of the present invention. In FIG. 13, a component same asthat of the first embodiment is provided with the same symbol and itsdescription is omitted.

In case of this embodiment, the contact face 113 c between absorptionbodies 130 and 140 is formed between the upper and lower ends of a jointpipe 180. Under the normal operating state, a gas-liquid interface L isformed nearby the upper end of the joint pipe 180. Therefore, also inthis configuration, the gas-liquid interface L is formed in theabsorption body 130 above the contact face 113 c. Therefore, when an inktank unit 200 is removed, the ink remaining in the joint pipe 180 isabsorbed in a negative pressure control chamber container as thegas-liquid interface L rises through the absorption body 130. Therefore,as shown for the conventional example, when the gas-liquid interface Lreaches the contact face 113 c, the ink absorption rate does not lowerand thereby, it is possible to smoothly absorb the remaining ink.

Moreover, in case of this embodiment, an absorption body 141 having acapillary force higher than that of the absorption body 140 is formed ona portion contacting with a supply port 131 by being brought intocontact with the absorption body 140. Therefore, it is possible toefficiently introduce the ink reaching the vicinity of the supply port131 by a capillary force of the absorption body 141. Furthermore, byforming the absorption body 141 of a fiber body having the main fiberdirection in the vertical direction in FIG. 13, it is possible todecrease the dynamic resistance of the ink toward the supply port 131and efficiently introduce the ink into the supply port 131.

Third Embodiment

FIG. 14 shows a sectional view of an ink-jet head cartridge of a thirdembodiment of the present invention. This embodiment is different fromthe first and second embodiments in the shape of a liquid supplycontainer.

Moreover, FIG. 14 shows a state in which an ink container 401 is held bya holder 350 having a negative pressure control chamber unit 300 so asto be removably from the holder 350. As shown in FIG. 14, in case of anink-jet head cartridge of this embodiment, the ink container 401comprises an integrated-structure housing 410 in which a concave portion452 for ID corresponding to two ID members provided for the negativepressure control chamber unit 300 is formed at two places and a jointport 330 serving as an ink supply port and fitted to a joint pipe 380 ofthe negative pressure control chamber unit 300 is formed and stores ink.Moreover, the ink container 401 completely keeps an airtight statebecause the joint port 330 is sealed by a film seal 362 when thecontainer 401 is not set to the holder 350.

Moreover, an O ring 363 is set to the root of the joint pipe 380. The Oring 363 generates an energizing force for pressing the lower portion ofthe back 411 of the ink container 401 against an ink-tank securingportion 355 of the holder 350 when the ink container 401 is set to thenegative pressure control chamber unit 300.

A gap is formed between the inner periphery of the joint port 330 andthe outer periphery of the joint pipe 380, which makes it possible tohold the film sheet 362 pierced by the joint pipe 380 and folded to theinside of the housing 410 of the ink container 401 between the innerperiphery of the joint port 330 and the outer periphery of the pipe 380.The O ring 363 not only generates the above-described energizing forcebut also prevents the ink stored in the ink container 401 from leakingfrom the gap formed between the inner periphery of the joint port 330and the outer periphery of the joint pipe 380. Because the negativepressure control chamber unit 300 serving as a capillary forcegenerating member storage chamber is the same as the negative pressurecontrol chamber unit 100 of the first embodiment except the portionrelating to the joint pipe 380, its detailed description is omitted.

In this case, the ink container 401 is made of a material not having aninner bag 220 deformed due to a negative pressure generated in acontainer such as the ink container 201 of the first embodiment andhardly deformed due to a negative pressure generated in a container.Therefore, the ink container 401 of this embodiment does not have aneffect by an inner wall 220 described for the first embodiment.

However, by applying the present invention also to the ink container401, it is possible to solve the above technical problem aboutsetting/removing.

Moreover, it is permitted to change the shape of the capillary forcegenerating member storage chamber shown for the first embodiment to theshape of that of the second embodiment. In this case, almost the sameadvantage as the case of the second embodiment can be obtained aboutsetting/removing of the ink container 401. However, to solve variousproblems on setting/removing, the first and second embodiment issuperior in adaptability for a synthetic ink supply performance and anenvironmental change. Therefore, as a result, configurations of thefirst and second embodiments are more preferable than the configurationof the third embodiment.

As described above, the present invention provides a liquid supplymethod using a liquid supply system including a liquid supply containerhaving a liquid storage portion for storing liquid in a closed space; atleast two capillary force generating members removable from the liquidsupply container, capable of storing liquid, made of fibers, andcontacted each other; an atmospheric air communication portion forcommunicating with atmospheric air; and a capillary force generatingmember container having a liquid supply portion for supplying liquid tothe outside; in which it is possible to smoothly absorb the liquidremaining in a communication portion for communicating the liquid supplycontainer with the capillary force generating member in the capillaryforce generating member container when removing the liquid supplycontainer from the capillary force generating member container bysetting the upper end of the communication portion above the contactface between the two capillary force generating members.

Moreover, it is possible to provide a liquid supply method making itpossible to consume the ink in an upper capillary force generatingmember and thereafter consume the ink in a lower capillary forcegenerating member, immediately stabilize the gas-liquid interface ofinjected ink by connecting a liquid supply container to a capillaryforce generating member container, and stably supply ink.

What is claimed is:
 1. A liquid supply system comprising: a capillaryforce generating member container having a capillary force generatingmember for storing liquid, an atmospheric air communication portion forcommunicating the capillary-force generation member with atmosphericair, a liquid supply portion for supplying liquid to an outside thereof,and a liquid communication portion for introducing liquid into saidcapillary force generating member container; and a liquid supplycontainer having a liquid storage portion settable to and removable fromthe capillary force generating member container and which stores liquidin a space closed except for a connection portion connectable to theliquid communication portion of said capillary force generating membercontainer; wherein said capillary force generating member includes atleast two liquid storage members made of fibers and contacted with eachother, the at least two liquid storage members being contained entirelywithin said capillary force generating member container; and wherein anupper end of the liquid communication portion is located above a contactsurface between the at least two liquid storage members.
 2. The liquidsupply system according to claim 1 wherein the contact surface ispresent below a lower end of the liquid communication portion.
 3. Theliquid supply system according to claim 1 wherein a dynamic resistanceof liquid in the liquid storage member above the contact surface issmaller than that of liquid in the liquid storage member below thecontact surface.
 4. The liquid supply system according to claim 1wherein a capillary force of the liquid storage member above the contactsurface is smaller than that of the liquid storage member below thecontact surface.
 5. The liquid supply system according to claim 1wherein a fiber density of the liquid storage member above the contactsurface is lower than that of the liquid storage member below thecontact surface.
 6. The liquid supply system according to claim 1wherein a main fiber direction of a liquid storage member constitutingthe capillary force generating member is almost horizontal while theliquid storage member is operated.
 7. The liquid supply system accordingto claim 6 wherein a layer of the liquid storage member having the mainfiber direction in an almost horizontal direction is present near to theupper end of the liquid communication portion.
 8. The liquid supplysystem according to claim 1 wherein the liquid storage members havedifferent capillary forces and the liquid storage member having acapillary force higher than that of the other liquid storage member isbrought into contact with the liquid supply portion.
 9. The liquidsupply system according to claim 8 wherein a main fiber direction of theliquid storage member in contact with the liquid supply portion isparallel with a liquid supply direction.
 10. The liquid supply systemaccording to claim 1 wherein the liquid communication portion is setabove the liquid supply portion.
 11. A capillary force generating membercontainer, comprising: a capillary force generating member for holdingliquid; a liquid communication portion to which the liquid is suppliedfrom a removable liquid containing vessel; an atmospheric aircommunication portion for communicating with atmospheric air; and aliquid supply portion for supplying liquid to an outside thereof,wherein said capillary force generation member is provided with at leasttwo liquid storage members made of fibers and contacted with each other,the at least two liquid storage members being contained entirely withinsaid capillary force generating member container, wherein a contactsurface between the at least two liquid storage members is present belowan upper end of the liquid communication portion; and wherein theremovable liquid containing vessel defines a substantially closed spaceexcept for a connection portion when the removable liquid containingvessel is connected to said capillary force generating member containerat said liquid communication portion, the connection portion beingconnectable to said liquid communication portion.